The biggest gain you'll get is faster memory, provided you have enough capacity to load all the weight into vram. The DGX sparks and Apple silicon memory bandwidth (and also memory access latency) drag down the decode speed quite a bit.

I have two GPU rigs both with 2x RTX Pro 6000, can get ~250 tk/s decode with deepseek-v4-flash in native mixed precision. For context, in antirez's dwarfstar project he only gets ~20-40 tk/s on the same model @ 2bpw on M5 Max.

The latter is for sure usable if it's your only option, but it's really hard for me to personally go back to speeds like that when I've experienced the former.

(Also worth noting dwarfstar only has experimental support for dspark spec dec, when that lands it will definitely give a big boost at higher acceptance rates)

It runs very quickly on my RTX 5090 fwiw. Whole thing is loading entirely into vRAM with a ~130k context size (the max) fitting as well.